Actuating mechanism



March 14, 1961 w. E. HIGGINBOTTOM 2,975,258

ACTUATING MECHANISM Filed Jan. 15, 1959 AQHIIIIIIIIII Illllllll Ii! lllllllll IMI Ill llllllllll INVENTOR. 'WILLIAM E. HIGGINBOTTO ACTUATING MECHANISM William E. Higginbottom, West Chester, Pa., assignor to Burroughs Corporation, Detroit, Mich., a corporation 'of Michigan Filed Jan. 13, 1959, Ser. No. 786,622

Claims. (Cl. 200-172) The invention hereinafter described and claimed has to do with actuating mechanisms for controlling movable members. More specifically, however, the invention relates to an actuating mechanism for electrical switch contacts.

In this present electronic age the use of electrical equipment has increased immeasurably. Because of this, heretofore acceptable faults of many commonly used electrical components have become intolerable, and such devices have become the subject of much research and engineering in an effort to overcome these faults so that their operation may be substantially faultless. Electrical switch actuators, for example, are found in most electronic and electromechanical equipment and their faultless operation is imperative.

Electromechanically operated business machines use many switches which are provided with bar type actuators to provide a larger target for the user to strike when actuating the switches in these machines. Switch actuators of the bar type, however, have presented a peculiar problem. That is, the pressure to actuate the switch is hurriedly applied and therefore may be greater at the terminal ends of the bar rather than directly over the switch actuating shaft, a condition often resulting in the actuating shaft binding in its bearing in a manner to resist actuation of the switch.

It is an important object of the present invention, therefore, to provide an improved actuating mechanism for a movable member when overcomes the abovementioned difliculty.

Another important object of the invention is to provide a novel reciprocable bar type switch actuator wherein the actuator is freely movable to actuate the switch regardless of which area of the actuator bar is pressed. 7

In acordance with the above objects and first briefly described the invention contemplates an actuating mechanism including an elongated shaft mounted for reciprocal movement by means of a narrow bearing embracing one of its ends and a flexible member supporting its other end whereby a bar type shaft actuator may be used without danger of the shaft binding in its mounting as a result of pressure applied off center of the shaft.

Further objects and advantages of the invention will be apparent from a consideration of the following description when taken with the accompanying drawings, in which:

Fig. l is a perspective view of a switch structure embodying the present invention;

Fig. 2 is a front elevational view of the apparatus shown in Fig. 1 with parts broken away to better show the invention; and

Fig. 3 is a fragmentary sectional view of a portion of Fig. 2.

The preferred embodiment of the invention is illustrated associated with an electrical switch 10 which may be of conventional design, including two or more switch 2,975,258 Patented Mar. 14, 1961 ton 11 extending out of the switch housing in line with the shaft 12 of the switch actuating mechanism constructed and arranged in particular accordance with the present invention.

As seen more clearly in Fig. 2 the switch is mounted upon a substantially T-shaped bracket 15 having a flange 16 turned outwardly along its top edge. Shaft 12 extends through a guide sleeve 17 and has a push bar 18 secured to and across its upper end in any convenient manner, such as by the set screw shown.

The inner diameter 19 of sleeve 17 is larger than the diameter of that portion of shaft 12 extending through the sleeve, and its upper end is provided with an inwardly turned flange terminating in a bore 20 of substantially the same diameter as shaft 12 providing a small or narrow bearing surface embracing the shaft for guiding its movement to actuate switch 10, as described later.

While other proportions may be used, in practising the invention, it has been found that with a .25" diameter actuating shaft, a bearing surface of .016 is quite satisfactory with a bore 20 of .260" diameter.

Sleeve 17 may be secured to flange 16 in any suitable manner. However, in the presently illustrated embodiment, it is attached by swageing over its lower edge or rim, as indicated at 21.

The lower end of shaft 12 is of slightly larger diameter than the upper end and is secured as by machine screw 23 and lock washer 24 to the intermediate portion 25 of an elongated spring leaf 26, the ends of which are secured to outwardly turned ear portions 27 and 28 of bracket 15, as by nut and bolt fasteners 29. The spring preferably is of sufficiently rugged structure to retain its shape under normal usage, and may be constructed of any suitable material, such as beryllium copper. To provide suflicient resiliency to the spring whereby it may be flexed either downwardly and upwardly, or even slightly to the right or left, if need be, the spring is provided with oppositely turned U-shaped loop portions 30 and 31 intermediate each of its terminal ends and the intermediate portion 25.

To maintain push bar 18 aligned with bracket 13 and to prevent turning of the shaft and push bar relative to the bracket, guide sleeve 17 is provided with diametrically opposite radial slots 32 and 33 for guiding the opposite ends of a pin 34 extending through and secured to shaft 12.

In the operation of this actuating mechanism, it will be seen that pressure on any part of push bar 18 will freely move shaft 12 in the direction to actuate button 11 of switch 10. If pressure is exerted on either terminal end of the push bar, shaft 12 will have a slight tendency to move in the opposite direction about bearing 20 as a pivot. However, spring 26is of suflicient rigidity to limit this movement to an extent preventing shaft 12 from binding in the small bearing portion 20 of sleeve 17, or from contacting the lower end of sleeve 17, regardless of where the pressure is exerted on push bar 18. When the perssure is removed from bar 18, spring 26 returns the actuator to its retracted inoperative position, as shown. Thus by providing the small bearing surface 20 spaced from the connection of the end of the shaft 12 is made free to reciprocate in its switch actuating movements without binding.

In the claims:

1. An actuating mechanism comprising: an elongated actuating shaft having one end by which it is actuated and an opposite end for actuating associated apparatus;

and means mounting said shaft for reciprocal movements; said last means comprising a narrow fixed bearing embracing said shaft adjacent said one of its ends, an

elongated flexible member secured transverse to the direction of movement of said shaft, and means connecting said opposite end of said shaft to said flexible member.

2. An actuating mechanism, comprising: an elongated actuating shaft; and means mounting said shaft for reciprocal movements; said last means comprising a narrow fixed bearing embracing said shaft adjacent one of its ends, an elongated flexible member secured transverse to the direction of movement of said shaft, means connecting the other end of said shaft to said flexible member, and a bar shaft actuator secured to said one end of said shaft transverse to the direction of movement thereof.

3. An actuating mechanism, comprising: a bracket; an elongated actuating shaft having one endv by which it is actuated and an opposite end for actuating associated apparatus; and means mounting said shaft on said bracket for reciprocal movements; said last means comprising a narrow bearing on said bracket and embracing said shaft adjacent said one of its ends, and a flexible member having edge portions secured to said bracket and a central portion secured to said opposite end of said shaft.

4. An actuating mechanism for a movable member, comprising: a bracket; an elongated actuating shaft; and means mounting said shaft on said bracket for reciprocal movements effective to actuate said movable member; said last means comprising a narrow bearing supported on said bracket and embracing said shaft adjacent one of its ends, and an elongated flexible member having its ends secured to said bracket and its intermediate portion secured to and flexibly supporting the other end of said shaft in a position for actuating said movable member.

5. An actuating mechanism for a movable member, comprising: a bracket; an elongated actuating shaft; means mounting said shaft on said bracket for reciprocal movements effective to actuate said movable member; said last means comprising a narrow bearing supported on said bracket and embracing said shaft adjacent one of its ends, an elongated flexible member having its ends secured to said bracket and its intermediate portion secured to and flexibly supporting the other end of said shaft in a position for actuating said movable member; and a bar shaft actuator secured to the said one end of said shaft transverse to the direction of shaft movement.

6. A construction according to claim 5 wherein said elongated flexible member comprises a spring leaf having bent portions between its ends and said intermediate portion.

7. A construction in accordance with claim 6 wherein said bent portions are in the form of opposed interconnected Ll-shaped portions.

8. In combination: a bracket; an electrical switch mounted on said bracket and having an actuating button; an elongated actuating shaft; and means mounting said shaft on said bracket for reciprocal movements effective to actuate said switch button; said last means comprising a flange on said bracket overlying said button, a narrow bean'ng supported on 'said flange and embracing said shaft adjacent one of its ends, and a flexible mem ber secured across the other end of said shaft with edge portions secured to said bracket and a central portion secured to the said other end of said shaft with said other end in a position for actuating said switch; said flexible member comprising a spring leaf having reversely bent portions between its ends and its intermediate portion.

9. A switch mechanism, comprising: a bracket; an electrical switch mounted on said bracket and having an actuating button; an elongated actuating shaft; and means mounting said shaft on said bracket for reciprocal movements effective to actuate said switch button; said last means comprising a flange on said bracket overlying said button, a sleeve member secured at one of its ends to said flange and through which said shaft extends in spaced relation to the walls thereof, a narrow bearing formed at the other end of said sleeve and embracing said shaft adjacent one of its ends, a flexible member secured across said bracket substantially parallel with said flange, and means connecting the other end of said shaft to the central portion of said flexible member and adjacent said button; said flexible member comprising a spring leaf having reversely bent portions between its ends and its intermediate portion.

10. A switch mechanism, comprising: a bracket; an electrical switch mounted on said bracket and having an actuating button; an elongated actuating shaft; and means mounting said shaft on said bracket for reciprocal movements effective to actuate said switch button; said last means comprising a flange on said bracket overlying said button, a sleeve member secured at one of its ends to said flange and through which said shaft extends in spaced relation with the walls thereof, a narrow bearing formed at the other end of said sleeve and embracing said shaft adjacent one of its ends, a flexible member secured across said bracket substantially parallel with said flange, means connecting the other end of said shaft to the central portion of said flexible member adjacent said button, said flexible member comprising a spring leaf having reversely bent portions between its ends and its intermediate portion, and a bar shaft actuator secured to and across said one end of said shaft adjacent said bearing.

Cataldo Nov. 18, 1952 Ford July 2, 1957 

